Method of barking slabs.



H. GUETTLER.

METHOD OF BARKING SLABS.

APPLICATION FILED NOV. 10. 1916.

Pamnted Nov. 20, 191?.

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METHOD OF BARKING SLABS. APPLICATION man NOV. I0, 1916.

m wmmao Patented Nov. 20, 191?.

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METHOD OF BARKING SLABS.

APPLICATION FILED NOV. 10, 1.91s.

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P M W Z w m P HERBERT GUETTLER, OF CHICAGO, ILLINOIS, ASSIGNOR T0 FIBER. MAKING PROCESSES, 01E CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

METHOD OF EARRING- SLAIBS.

of Illinois, have invented certain new and useful Improvements in .Methods of Bar ing Slabs; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

It is possible to remove bark from logs or blocks of wood preparatory to use of the wood in the 'paper making industry by tumbling the logs or blocks in a rotating drum which preferably, but not necessarily, is partially immersed in water held in a suitable tank. The bark thus removed from the wood may'be allowed to escape from the drum into the tank through longitudinal slots in the drum.

It has not heretofore been customary to bark slabs, edgirigs or like-mill waste in such a device, because such thin pieces would work themselves into the slots of the drum 'as ordinarily arranged, thereby closing up the slots and even projecting through far enough to strike against the sides ofthe tank or the driving mechanism, thereby preventing-free rotation of the drum.

It is possible, however, as hereinafter disclosed, to provide a wood barking, drum of such construction that while the separated bark can escape freely from the drum' through longitudinal slots, these slots are of such construction and so protected that the slabs, or-the like, will not close them and will not work out through them. -With barking drums of this special construction, 1

particularly when operated-by the method hereinafter disclosed and claimed, it is possible to efi'ectively and economically bark slabs, edgings and similar fiat sided or thin pieces of wood, and thereby niake available for use in the paper making industry ra'w Speciflcati'on of Letters Patent.

from and all on each other.

This fact, and

Patented Nov. 26D, M911 "3.

Application filed November 10, 1916. Serial No. 130,517.

moving outer and inner' bark from logs, and particularly from slabs, edgings and like mill waste, are fully appreciated in the paper making industry.

The apparatus whereby the method herein claimed may be carried out comprises a rotating drum, the cylindrical wall of which is built up out of strips, angle bars, or the like, of such form or so arranged as to overhang or partially cover the slots between ad-. acent bars, preferably forming the slot into a tortuous passage through which the bark may freelyescape, and yet into which the slabs or edgings will no enter, or at least will not project throug and strike stationary parts of the apparatus. If slabs, edgings, or wood of like character, be charged into such a drum, and be tumbled and caused to cascade therein b rotation of the drum, there will result, as have found in practice, a certain rather definite packing of the slabs, or like flat pieces, into a compact, foliated mass, whereof the superimposed or stacked slabs, edg- I ings, or the like, vconstitute the daminae. Merely rolling such a pack or folia ed' mass over and over' in the drum as the drumrotates, does not efiiciently or efl'ectively remove the bark, for to secure good barking action in apparatus of this type, there should be a sliding and scraping of each piece ofwood over its neighbors, as the pieces cascade from the upwardly moving side of the drum into the water at the bottom (or against the opposite side of the drum, if no water is being used in the tank.)

Pieces such as 'slabsor edgings which have fiat surfaces are liable to pack together and at best slide or slitheron each other without material concussions such as occur when more nearl round pieces roll over and away I have found that a charge composed only or principally of slabs and edgings does not operate satisfactorily, and I have discovered'the fact that the addition of certain other pieces of wood to such a charge will improve 1ts op-' eration.

(Hill I have found that if there be present with the tumbliig slabs, or the like, blocks of larger size In proper proportion, the packing. or foliating of the slabs willin large measure be prevented the concussive action will be improved, and a much more effective and efiicient barking action will be secured. These larger blocks mag be logs of the size and lengths now commonly barked in rotating drums in preparation for their manufacture into wood pulp.

They maybe in barked or unbarked condition when initially charged into the intake end of the rotating drum, and after tumbling therein and delivery from the disscri tio which is to be taken in conjunction with e accompanying drawings, wherein Figure 1 is a plan view of a barking drum through which slabs, edgings, or 'the like, may be passed for tumbling 1n the presence of larger blocks.

' Fig-2 is a side elevation of the same.

Fig. 3 is an end elevation.

Fig. 4 is a cross section on the line 44 of Fig. 2. I

Fig. 5 is a fragmentary section of the drum showing how the angle bars are shaped and arranged to guard the slots against the entrance or passage of thin pieces of wood.

35.4 Figs. 6, 7 and 8 illustrate alternative arrangements for guarding the slots. I

Fig. 9 shows a detail at the end of the drum for guarding the clearance space between the drum and an adjacent barrier.

The apparatus shown in the drawing comprises a drum 1 cylindrical in shape and open at both ends. The'drum is arranged for rotation in a tank 2 adapted to ntain water and having. a concave bottom substantially concentric throughout with the drum and spaced therefrom but a relatively short distance.

The cylindrical drum is composed of a,

plurality of rings 3 towhich are secured the bars 4, which constitute the side or cylindrical wall of the drum. In the embodiment illustrated in Fig. 5, these bars 4 are .ob-

tuse angle bars havingtheir web's rivetedto the inside of rings 3 and spaced apart, as

shown in Figs. 4 and 5, to form long, narrow slots through which the separated bark is delivered from thedrum.

The flanges of these obtuse angle bars are on the trading edges of the ars, so, that each overhangs its adjacent sl t. I The slot is therefore not radial, butapproach'es the itan'gentlal, and while the bark can find a a ready exit through the slots when the drum is rotated in the direction indicated by the arrow (Fig. 5), the slabs, edgings, or the like, do not find a ready exit, but slide over from one bar to the next.

In the embodiment illustrated in Fig. 6,

i the bars 40 have their flanges at right angles to their webs, and the desired overhang for the slots is secured by inserting wedges 41 between the web of each bar and the adjacent web of the encircling ring 3, thereby tilting the bars inward at their forward edges and backward at their. trailing edges, and so covering up the bark discharging A slots to the extent necessary to prevent the slabs from stopping up the slots or projecting through to the outside of the drum. 1 With either of the embodiments illustrated in Figs. 5 and 6, an additional bar may be positioned on the outside of each slot to serve as a battle and convert the slot' into a tortuous passage through which only the bark can pass. Asshown in Fig. 7, these additional bars 42 may be in the form of rods passed through holes in the flanges of rings 3 and lying against the'webs of those rings opposite the gap between the adjacent pair of angle bars, or, as shown in Fig. 8, the additional bars 43 may be fiat and riveted to the Webs .of rings /3 to cover up or restrict the adjacent bark discharging slot to the extent desired. These additional outside bars, particularly if in the form shown in Fig. 8, add somewhat to the rigidityof the drum, and as the drum may have a length 0f-.say '20 or 30 feet, and a diameter of say 1.0 to 12 feet, and weighs several tons, the rigidity of it under the stresses'of a full load of wood is a matter of importance. The drum 1 is supported by flexible, endless elements, such as chains 5, which engage smooth rings 6 with which the drum is provided, and pass over smooth traction wheels 7 and 8, which are supported on a suitable frame 9. These traction wheels are secured to independent axles, and'the axles 10 of wheels 8 are preferably ournaled in suitable take-up bearings each of which is pressed outward by a spring 11 having its inner end seated on a screw 12, whereby it can be ad- ,justed with a wrench to-increase or decrease the tension on the spring, thereby sliding the bearing with its axle 10 either inward or outward, and in this manner adjusting the tension on eachv individual supporting chain of which there may be four, as illustrated in the drawings. Not only can the slack of the chains thus be taken up independehtly and the load evenly distributed on the several chains, but shocks and stresses incident to rotation of the drum are to a certain extent taken up by the springs, thereby protecting framework 9 and other as-- sociated parts. I I

As a means for rotating the drum, there mamas is provided near its middle, an annular sprocket 13 bolted between the flanges of the two central drum rin 3, which for this purpose are placed side y side with their flanges opposed. Engaging with the sprocket is a driving chain 14 which passes over a driving sprocket 15 secured to a shaft 16. This shaft ispreferably positioned above the upwardly moving side of the drum, and is driven in suitable manner, as by a sprocket 17 and chain 18. The driving chain may be slack .on the following side, thereby giving the drum freedom of movement when springs 12 are adjusted or yield during normal operation of the apparatus, In

order to prevent the drum from swinging laterally, it is provided adjacent its ends with guide rings 19 which are engaged by the flanged guide rollers 20, rotatably mounted, upon the frame 9 at the sides of .the drum.

The slabs, edgings or wood of like character, from which thebark is to be detached, are introduced into one end of the drum by means of a chute 21, amh after the bark has been removed, are delivered from the other end of the drum to a chute 22, preferablyin the form (if-a" id or grating, and

down this they slide whlle'being washed 0E 30 with jets of water from a pipe 23. The barked wood is ultimatelydelivered to an endless conveyor 24 by which 'it may be transported to other parts of; the -mill. Thre is a second conveyor leadin from the discharge end of the drum to ,the lntake end thereof for purposes hereinafter explained.

The plurality of bark discharging openings formed in the cylindrical surface of the drum between the angle bars 4, are of such size that the pieces of detached bark may pass freely therethrough and into the tank ofwater. Secured to the outer surface of the are a pluralityof paddles or flights 26, preferably in the form of combs or'forks. As the drum rotates these flights sweep through the water in tank 2 and r emove therefrom the pieces of bark which have passed into-the tank through the openings 1n the drum. This barkis discharged over the side wall 27 of the tank and received in compartment 28 which has a horizontal drain plate 29 and a scraping conveyer 30 for transporting the bark toward one end of the drum for ultimate delivery to a drylng ap other industrial purposes. The water drain ing oil through plate 29 is collected in a drain 31 and conveyor away. By support ing the drum'upon thechams, as shown,

aratus, or the like, whereby the bark is rendered suitable for fuelorfor and the and thus thebottom of the tank interfere with removal of the bark from drum.

Near the ends of the drum the combshaped flights 26 may be replaced by imperforate baflies 32 of spiral form, secured to the outside of angle bars 4:, and acting to propel inward toward the next adjacent section of the .drum such bark as nnight otherwisecollect near-the ends of the tank or interfere with adequate clearance between the ends of the drum and the closures therefor.

By the method of my present invention, the charge of slabs, edgings, or like mill waste, is tumbled inthe rotating drum while mixed with an appropriate quantity of blocks of larger size, serving to insure efiicien't and effective bar ing action, and serving to substantially prevent packing foliating 'of the fiat pieces, and giving to the massas a whole a heterogegeous character conducive to good scraping and scrubbingaction and 00d concussion as the drum vrotates. Theselocks of larger size may have a length of say two feet and a diameter of say six inches, and may be PI GSBIIt in the drum to the extent of say a quarter the total volume of the tumbling mixture, though considerable variations from these sizes'and proportions are permissible.

As the drum rotates, the charge is rotated until its upper surface assumes a certain critical angle, as indicated somewhat diagrammatically in Fig. 4:, after which the slabs and blocks of wood tumble over one another and rub over and pound on one another in' an irregular way, but in such manner that the bark becomes detached. The quantity of wood which can be treated, and consequently the angle of inclination which the surface of the charge assumes during the operation, depends upon the quality and character of the wood. lln orderthat the machine may be adapted to treat difi'eren't' quantities of .wood, or dif-,

ferent qualities of wood, adjustable means are provided adjacent v the dlscharge end of the, drum to vary the height of the wood within the drum As shown, the end posts 33 of frame 9 are adapted to support transversely extending planks 34 bolted thereto. When the planks are in place, they are as close to the open discharge end of the drum as is permissible with adequate clearance, height of the barrier thus built up by placing one plank aboye another, deter mines the height to which the tumbling wood pile must be built within the drum the end barrier.

To prevent small pieces of wood from before the wood begins to tumble out over working into the clearance gap between.

either end of the. drum and its adjacent tilt and

56 drum to wet .down and wash off the wood plank barrier, and there becoming wedged and either stopping rotation of the drum or injuring some part of the apparatus, the

is provided a guard 35 attached to the a jacent barrier and overlapping the .end of the drum sufficiently to cover the clearance gap. In Fig. 9, this guard is in the form of an angle bar fastened to barrier 34 and the wood thoroughly soaked down without,

however, permitting it to float. By thus proportioning the amount of water'to the quantity of Wood being treated, the water acts as a support for .the wood and relieves to a great extent the weight which the chains 5 would otherwise be called upon to support. In order to vary'the amount of water within the tank, the edge 27 thereof comprises a plurality of removable sections placed one above another. These sections form a dam and provide ready means for.

varying the level of water within tank.

With some kinds of wood, as, for stance, hemlock, it is desirablat times to efiect barking without periodically immersing the wood in water. By thus workingin a dry way, the bark comes from the apparatus in drycondition and needs no treatment to render it suitable foruse as fuel.

The apparatus here disclosed is readily adaptable for dry barking and to this end tank 2 is provided-near its center with an outlet chamber 36 controlled by a valve or gate 37 in a discharge pipe leading to a drain channel 38. andconforming to the curved interior of the tank, and flush therewith, is a removable grid or grating 39 through which the bark will not pass and from which the bark will be swept away by the. moving flights or combs26. When thus operatingin: a dry way, there is advantage in spraying the wood with water prior to its exit from the drum, to wash off adhering dust and bits of bark, and to this end spray pipe'23, may have openings along its side as well as along its bottom, and .can'be used for projecting water into the adjacent open end of the when it is approaching delivery from the drum.

' A -When working a dry way, but more especially when ,working in the wet way, the I blocks of wood which have been added to the slabs to prevent packing, have atendency togravitate toward or stay near the underside of the cascading mixture. Conse- Over this chamber 36 quently, the smaller and lighter slabs, or the like, pass through the drum, and are discharged on grating 22 more readily than is thecase with the larger blocks. But when the blocks or larger pieces do come from the drum, they may be recovered by a workman standing at the foot of grating 22 and may be deposited in t conveyer 25 and thereby be carried back rom the discharge end of the drum to its intake end for action again on fresh slabs to be barked. The action on the slabs in the drum seems to be approximately the same whether the incoming blocks have previously been barked or not, but in charging slabs,- edgings, or like mill waste, together with larger blocks, into the drum, it is important to regulate the relative quantity of each so that when tumbli in the drum and flowing therethrough an out at the discharge end, there will be maintained proper relative proportions of slabs and blocks 'to. effect the desired result of breaking up the slab packs and causing the slabsor the like to tumble or cascade in bing, pounding, and scraping on adjacent slabsand blocks, to effect thoroughhnd eflilike.

I claim 1. The method of-barking slabs, edgings or like mill waste, which consists in progressively passing the material through a rotating drum and there tumbling it with blocks 1 the material continuously into and out of a.

rotating drufn and therein tumbling it with -wood of larger size proportioned inquantity cient removal of bark from the slabs or the irregular manner, and With effective rubto prevent objectionable packing of. the material while cascading in the drum as it rotates; substantially as described.

-3. The method of barking slabs, edgin'gs or like mill waste, which consists inchargr ing the materialand wood blocks of larger size into one end of a continuously rotating drum and tumbling the. mixture until the material is barked -and delivered from the other end of the drum, the proportion of material to larger blocks being such. as to insure effective concussion and cascading of the material and to prevent it from objectionably packing together while passing through the drum; substantially asv de- .scribed. f

4- The methodiof barking slabs, edgings or'likemill. waste, which consistsin' charging the material and wood blocks of, larger sizeintofone end of 'a rotating drum, .tu'mblingsaid mixture therein, ultimatelydeliveringsaid material and-blocks therefrom,

mamasreturning said blocks for recharging into and like mill waste, which consists in tumthe drum, and maintaining the flow of bling it in a rotating drum while mixed with 10 blocks through the drum in such proportion Wood blocks of larger size to the extent of to the flow of said material therethrough as about one quarter the total Volume of the 5 to insure efiective cascading and freedom tumbling mixture, substantially as described. from objectionable packing of the slabs; Intestimony whereof I aifix my signature. substantially as described.

5. The method of barking slabs, edgings I I HERBERT GUETTLER. 

